A currently known breath-training device is comprised of a respiratory tube; a low-frequency mechanical air oscillation generator housing an oscillation chamber with an input channel, shaped as an upwardly extending saddle-shaped body of revolution (“saddle”) containing a spherical ball and connected to a respiratory tube, and to an output channel that vents into the ambient atmosphere; and a tubular attachment communicating with the respiratory tube via an inhalation valve (RU 2147906 C1, A63B33/00, 2000). The main disadvantage of that device is difficulty of regulation of the resistance to the exhaled airflow. Currently, the resistance is regulated by the position of the spherical ball in the input channel of the oscillation chamber, which decreases the efficiency of the training process.